Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Date: Wed, 24 Sep 2014 18:28:35 +0000 (UTC)
From: "Marcus Eriksson (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Message-ID: <JIRA.12707688.1397130824000.114321.1411583315730@Atlassian.JIRA>
In-Reply-To: <JIRA.12707688.1397130824000@Atlassian.JIRA>
References: <JIRA.12707688.1397130824000@Atlassian.JIRA>
 <JIRA.12707688.1397130824490@arcas>
Subject: [jira] [Commented] (CASSANDRA-7019) Major tombstone compaction
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-7019?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14146685#comment-14146685 ] 

Marcus Eriksson commented on CASSANDRA-7019:
--------------------------------------------

[~kohlisankalp] ill post a proof of concept patch for option 1 in the description tomorrow, idea is to basically run a major compaction, but have the compaction strategy decide on an 'optimal' sstable distribution for the strategy instead of just creating a big one, for LCS it simply fills levels from level 1 and up. For STCS it will create sstables where one has 50%, one 25% of the data, etc until the sstables get too small.

This is mostly for the "oh crap we have a ton of tombstones and need to get rid of them"-case, not for the day-to-day case, need to figure out something more for that (like your idea perhaps)

> Major tombstone compaction
> --------------------------
>
>                 Key: CASSANDRA-7019
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7019
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Marcus Eriksson
>            Assignee: Marcus Eriksson
>              Labels: compaction
>
> It should be possible to do a "major" tombstone compaction by including all sstables, but writing them out 1:1, meaning that if you have 10 sstables before, you will have 10 sstables after the compaction with the same data, minus all the expired tombstones.
> We could do this in two ways:
> # a nodetool command that includes _all_ sstables
> # once we detect that an sstable has more than x% (20%?) expired tombstones, we start one of these compactions, and include all overlapping sstables that contain older data.


--
This message was sent by Atlassian JIRA
(v6.3.4#6332)